Copolymers for acrylic fibers having improved basic dyeing properties comprising acrylonitrile, a cinnamic acid and vinylacetate or vinylidene chloride



United States Patent CGPGLYMERS FOR ACRYLIC FIBERS HAVING 1M- PRUVEDBASIC DYEHNG PROPERTIES COMPRIS- ING- ACRYLGNITMLE, A CINNAMIC ACID ANDVINYLACETATE 0R VENYLIDENE CHLORIDE Corrado Mazzolini and Sergio LoMonaco, Mestre, Venezia, Italy, assignors to Monsanto Company, St.Louis, Mo, a corporation of Delaware No Drawing. Continuation-impart ofapplication Ser. No. 260,838, Feb. 25, 1963. This application Apr. 8,1963, Ser. No, 271,467

28 Claims. (Cl. 260-895) This application is a continuation in part ofUS. application Ser. No. 260,838, filed Feb. 25, 1963 in the names ofCorrado Mazzolini and Sergio Lo Monaco, now abandoned.

The present invention relates to new and valuable fiberformingcompositions, including copolymers of acrylonitrile and blends thereofwhich are suitable for the production of fibers having improved dyeingproperties, and in particular improved basic dyeability.

It is known that the polymers and copolymers of acrylonitrile with othervinyl monomers such as vinyl acetate, methyl acrylate or methacrylate,and vinyl chloride as well as blends of these polymers and copolymerswith other polymers and copolymers of monoethylenically unsaturatedmonomers are suitable for the production of iibers having excellentphysical and textile properties. However, these polymer compositions aresubject to certain inherent disabilities, including that of sufiicientdye affinity to enable the development of satisfactory colors by meansof basic or cationic dyestuffs, which greatly restrict their utility inthe fabrication of general purpose fibers. The deficiency of fibers madefrom these polymer compositions insofar as it relates to theirdyeability with basic or cationic dyestuffs arises since, as the solegroups reactive with the dyestuffs, the acrylic polymer compositionscontain the sulfonic or sulfuric terminal groups arising from thefragments of the redox catalyst employed in the polymerization of thesepolymers and copolymers.

The dyeability of fibers formed from such acrylic polymer compositionswith suitable basic or cationic dyestuffs, i.e. dyestuffs having a basicfunction which is reactive with the acid groups indicated above,therefore is inversely proportional to the length of the polymericmacromolecule since, the longer the molecules of the polymer, the lessnumerous the functional groups terminating the chains. However, it isnot possible to obtain fibers of satisfactory physical properties byusing polymers of very low molecular weight, as would be desirable fromthe standpoint of dyeing. Therefore, it is necessary to be satisfied inpractice with a compromise between the two requirements, by limiting themolecular weight of the polymeric values which would not be the mostsatisfactory from the standpoint of the properties of the fiberobtained. Furthermore, even with these low values of molecular Weightthe dyeability of the fiber with basic or cationic dyes is still notentirely satisfactory, since it is not possible to obtain a very intenseshade of color such as required in certain applications.

In order to increase the dyeability of acrylic polymer fibers, it hasbeen proposed to employ in the polymerization monomers having a freeacid function which, upon being polymerized together with acrylonitrileand other vinyl monomers, give rise to copolymers having, in addition tothe terminal groups, other acid groups to which it is possible to fixthe basic dyestufis. It has also been proposed to produce polymers orcopolymers of vinyl monomers having the free acid function for purposesof blending with acrylonitrile polymers or copolymers otherwise quiteWeakly dyed by basic or cationic dyestuffs. As comonomers for thispurpose, i.e. direct polymerization with the acrylonitrile or othervinyl monomers to produce acrylic copolymers or for producing a blendingpolymer, there have been proposed various unsaturated carboxylic acids,or their corresponding anhydrides, including acrylic acid, methacrylicacid, itaconic acid, and the like. All of these monomers have thedrawback of producing greater color in the polymers produced and thefibers spun therefrom, as Well as adversely affecting the stability ofthe polymers and fibers produced to heat, and this effect has been foundto be greater With the higher the percentage of carboxylic acid monomeremployed. Therefore, from this standpoint it is desirable to obtain themaximum increase of dyeability by adding the minimum amount of acidmonomer to the mixture of monomers for the production of the copolymersand blending polymers.

It has now surprisingly been found that cinnamic acid and itsderivatives, namely acids of the general formula in which R represents alower alkyl or halogen radical and n represents an integer of from 0 to3 inclusive, not only readily copolymerize with acrylonitrile and othervinyl monomers, but are also the most effective of all the acidsindicated above in increasing the basic dyeability of the acryliccopolymers or blends derived therefrom.

By copolymerization with cinnamic acid or its derivatives the dyeabilityof the acrylonitrile copolymers can be increased as desired, and smallpercentages, not greater than 2% by weight of the polymer composition,are sufiicient to give the improvements in dyeability which are desiredin practice. Moreover, the cinnamic acid containing copolymers may beblended with other acrylonitrile polymers or copolymers which are notdyeable with basic dyes to produce a resulting polymer blend morereadily dyeable with basic dyes. Furthermore, at these low percentagescinnamic acid or its derivatives do not change the color of the polymer,polymer blend or of the fibers obtained therefrom.

For the purposes of the present invention it has been found thatcinnamic acid and derivatives thereof are suitable to accomplish thedesired objects, namely carboxylic acids of the general formula in whichR represents a lower alkyl radical or a halogen atom, preferaby chorineor bromine, and n represents an integer of 0 to 3 inclusive. It isapparent that the anhydride of cinnamic acid can likewise be employedwhen the polymerization is conducted in the presence of Water, as is thenormal practice in the solution, emulsion, or suspension polymerizationof acrylonitrile copolymers. Examples of suitable acid monomers includecinnamic acid and derivatives thereof, such as p-methyl cinnamic acid,p-ethyl cinnamic acid, p-isopropyl cinnamic acid, o-methyl cinnamicacid, m-ethyl cinnamic acid, 2,4-dimethyl cinnamic acid, 2,4-diethylcinnamic acid, 3,5-dimethyl cinnamic acid, 3,4,5-trimethyl cinnamicacid, 2,4,6-triethyl cinnamic acid, 2,3,5-triisopropyl cinnamic acid,13-, m-, or o-chloro cinnamic acid, p-, m-, o-bromo cinnamic acid,2,5-dichloro cinnamic acid, 2,4-dibromo cinnamic acid, 3,4,5-trichlorocinnamic acid, 2,4,6-tribromo cinnamic acid, and the like.

In the preparation of copolymers of the above carboxylic acids andderivatives thereof and acrylonitrile it has been found desirable to usefrom 0.05 to 2 percent by weight of the polymeric composition and topolymerize same in the presence of at least 80 percent of acrylonitrileand up to 19.95 percent of at least one other monoolefinic monomercopolymerizable therewith. It has also been found that the abovecopolymers of acrylonitrile and cinnamic acid or derivative may beblended with other non-basic dyeable acrylonitrile polymers to produce abasic dyeable fiber-forming polymer composition. In accordance with thismethod the cinnamic acid or derivative is copolymerized with at least 80percent acrylonitrile and up to 19.95 percent of at least one othermonoolefinic copolymerizable monomer in the same manner as above, andthereafter blended with the non-basic-dyeable acrylonitrile polymers ina proportion such that the final total polymer composition containsbetween 0.05 percent and 2.0 percent of the cinnamic acid or derivativemonomer units in the total polymer composition.

For example, the fiber forming polymer may be a copolymer of from 80 to99.95 percent of acrylonitrile, up to 19.95 percent of anothercopolymerizable mono-olefinic monomer, and from 0.05 to 2.0 percent ofthe cinnamic acid or derivative monomer, all in polymerized form.Suitable copolymerizable mono-olefinic monomers include acrylic,alpha-chloroacrylic and methacrylic acids, the acrylates, such as methylacrylate, ethyl acrylate, butyl acrylate, methoxymethyl acrylate,beta-chloroethyl acrylate, and the corresponding esters of methacrylicand alpha-chloroacrylic acids; vinyl chloride, vinyl bromide, vinylidenechloride, 1 chloro 1 bromoethylene; methacrylonitrile; acrylamide andmethacrylamide; alphachloroacrylamide, or monoalkyl substitutionproducts thereof; methyl vinyl ketone; vinyl carboxylates, such as vinylacetate, vinyl chloroacetate, vinyl propionate, and vinyl stearate;N-vinylimides, such as I l-vinylphthalimide and N-vinylsuccinimide;methylene malonic esters; N-vinyl carbazole; vinyl furane; alkyl vinylesters; vinyl sulfonic acid and vinyl benzene sulfonic acids; ethylenealpha, beta-dicarboxylic acids or their anhydride or derivatives, suchas diethyl citraconate, diethyl mesaconate; styrene; vinyl naphthalene;vinyl-substituted tertiary N-heterocyclic amines, such as thevinylpyridines and alkyl-substituted vinylpyridines, for example,Z-methyl-S-vinylpyridine, and l-vinylimidazole and alkyl-substitutedl-vinylimidazoles, such as 2-, 4-, or S-methyl-l-vinylirnidazole; andother mono-olefinic copolymerizable monomers.

As indicated above, the polymer composition can also be a blend of oneof the above-described copolymers of cinnamic acid or its derivativeswith acrylonitrile and/or one or more additional copolymerizablemonoolefinic monomers together with from 2 to 20 percent of a copolymerof to 70 percent acrylonitrile and 30 to 90 percent of at least oneother copolymerizable mono-olefinic monomer as indicated above.Preferably, when the polymer comprises a blend, it will be a blend offrom 80 to 98 percent of the first described copolymer, i.e., thatcontaining acrylonitrile, cinnamic acid or its derivatives, andalternatively, one or more additional vinyl monomers, with a suificientamount, from 2 to 20 percent, of a second copolymer of from 10 to 70percent acrylonitrile and from 30 to 90 percent of a vinyl-substitutedtertiary N-heterocyclic amine, such as 2-methyl-5-vinyl pyridine orl-vinylimidazole, to give a blend having an overall vinyl-substitutedtertiary N-heterocyclic amine content of from 2 to 10 percent, and anoverall cinnamic acid or derivative content of from 0.05 to 2.0 percent,both based on the weight of the blend.

As a means for evaluating the basic dyeability of the copolymers andblends obtained, they are dyed at 100 C. for 2 hours with a solution of7 grams per liter of a typical basic dyestuff, Sevron Blue 2 G (ColorIndex Basic Blue 22), and a quantity of dyestutf fixed is measured.Experience has shown that this measurement is in agreement with thedyeability of the fibers obtained. This measure has been selected,rather than the measurement of the dyeability of the fibers, since thelatter depends on the interaction of several other variables, such asthe orientation stretch to which the fiber has been subjected, thefinishing agents applied to the fiber, final treatments undergone by thefiber, such as texturing, heat setting, after-stretching, and so forth.By measuring the dyeability of the polymer, there is obtained a veryprecise and more significant indication of the influence on thedyeability of the constitution of the polymer itself, as has beenexplained in the paper delivered by C. A. Bowers and T. H. Guion at themeeting of the Fiber Society at West Point, N.Y., on Oct. 13, 1961,entitled, Equilibrium Absorption Studies of Cationic Dyes onExperimental Acrylic Polymers.

Dyestuffs suitable for use on the polymer compositions of the presentinvention are quite extensive. For example, for use on the copolymers ofacrylontrile containing the indicated amounts of cinnamic acid or itsderivatives practically any basic or cationic dyestuif can be used fordyeing the acrylonitrile copolymers under normal conditions, which arewell known to one familiar with the dyeing art. On the blendcompositions a great many of the basic dyestuffs will functionsatisfactorily. Among these are Fuchsine N Powder (C. I. Basic Red 9, C.I. 42,500), Genacryl Pink 3G) C. I. Basic Red 14, Genacryl Red 63 (C. I.Basic Violet 7, C. I. 48,020), Sevron Brilliant Red 313 (C. I. BasicViolet 15), Sevron Brilliant Red 46) C. I. Basic Red 14), Sevron Red GL(C. I. Basic Red 18), Sevron Red L (C. I. Basic Red 17), Genacryl OrangeG (C. I. Basic Orange 21, C. I. 48,035), Sevron Yellow R (C. I. BasicYellow 11, C. I. 48,055), Sevron Yellow 3RL (C. I. Basic Yellow 15),Sevron Blue BGL (C. I. Basic Blue Sevron Blue B (C. I. Basic Blue 21),Sevron Blue 26 (C. I. Basic Blue 22), Sevron Brown YL (C. I. BasicOrange 26), and many other basic dyestuffs for which Color Index numbersare not currently available.

The copolymers of cinnamic acid and its derivatives together withacrylonitrile and/ or other mono-olefinic copolymerizable monomers maybe prepared by mass, solution, suspension or emulsion polymerizationprocedures in the various manners well known in the art. A preferredmethod of polymerization involves a reaction in suspension in aqueousmedium in the presence of suitable freeradical producing catalysts, andpreferably redox catalyst systems. As catalysts, the peroxy catalystsuch as the peroxides, persulfates, perborates and the like, both oiland water-soluble types, as well as azo derivative catalysts may beused. The preferred catalyst is a redox catalyst system employing as areducing agent sufur dioxide, sodium bisulfite and other compounds ofsulfur in the lower valent state along with the persulfate,percarbonate, peroxy, and perborate catalysts.

The polymers of the present invention may be spun into fibers fromsolutions in any of the well known acrylonitrile polymer solvents, suchas N,N-dimethylformamide, N,N- dimet hylacetamide, ethylene carbonate,gamma-butyrolactone, moist nitromethane, tetramethylene sulfone,dimethyl sulfoxide, dimethyl sulfone and the like as well as aqueoussolutions of sodium thiocyanate, zinc chloride, lithium bromide, etc.Furthermore, the compositions of the polymers of the present inventionin any of the acrylonitrile polymer solvents may be extruded or spuninto filaments and fibers 'by any of the known methods for extrudingsuch polymeric solutions, such as wet spinning, wherein the solution isextruded below the surface of the coagulating bath, dry spinning whereinthe solution is extruded through a spinneret into a tower containing acounter-flowing extractant gas, usually heated, or dry jetwet spinning,wherein the solution is extruded above the surface of a coagulating bathand the filaments collected below the surface of same. The filaments andfibers formed from the acrylonitrile polymer compositions of the presentinvention demonstrate the increased basic dyeability possessed by thepolymers prior to extrusion and likewise demonstrate the superior fiberphysical properties detailed above.

Millieqnival.

ample 1, copolymers containing cinuamic acid copolymerized in accordancewith the present invention, Examples 2-7, and copolymers containingother comonomers having a carboxylic acid function, Examples 8-10, areset forth in the following table:

TABLE 1 Original color of Acid Comonomer (as @0011) Percent Sevronpolymer Example dded of coby weight. [N] Blue, 2G

monomer per lixod Purity Brightness 100 grams of Percent monomer total 1None 1. 54 11.8 1. 7 93.4 2.0 0.3 1.70 13.3 1.9 95.2 3.4 0.5 2.00 11. 71.3 95.9 3. 4 O. 5 1. 58 16. 9 2.0 94. 4 3. 4 0. 5 1.39 19. 1.6 92. 26.8 1.0 1.00 18.5 1. 7 94.0 13. 2.0 1. 79 25.0 2. 6 94. 2 6. 9 0. 5 1.6014. 2 1. 8 94. 5 9 Crotonic acid G. 7 0.575 1. 47 11. 7 2.0 94. 4 10Itaconic acid 6.9 0. 1. 60 16.0 1. 9 94. 6

mers and blends in accordance with the invention and, by way ofcomparison, copolymers free of acid co-monomers or containing otherco-monomers having a carboxylic acid function which do not fall withinthe scope of the present invention.

Examples 1l0 Into a three liter polymerization reactor, there arcontinuously fed two aqueous streams containing an amount of potassiumpersulfate catalyst varied in accordance with the intrinsic viscosity[N] which it is desired to obtain, from 0.2 to 0.6 percent by weight ofthe monomer mixture, and an amount of sulfur dioxide activator,partially neutralized with sodium bicarbonate, varied in accordance withthe intrinsic viscosity desired, from 1.2 to 3.5 percent by weight basedon the monomeric mixture, and a stream of monomers composed of a mixtureof 92 percent acrylonitrile and 8 percent vinyl acetate, plus anadditional amount of the vinyl carboxylic acid introduced to increasethe dyeability. The amount of water added is at a rate of 2.3 liter-s(2300 grams) per hour and the amount of mixed monomer stream is at arate of 0.5 liter (406 g.) per hour. From an overflow tube the aqueoussuspension of a polymer obtained is discharged, filtered, repeatedlywashed with water and with acetone and then again with water in order toeliminate all foreign substances and unreacted monomers, and thereafterdried in an oven at 80 C. for twelve hours. Under the standardpolymerization conditions described there are obtained about 300 gramsper hour of copolymer, in which the acrylonitrile and the vinyl acetateare copolymerized in approximate prop-ortions of 94 parts ofacrylonitrile and 6 parts of vinyl acetate. The following determinationsare carried out on the resulting polymers:

(a) Intrinsic viscosity [N] in dimethylformamide, expressed indeciliters per gram from which there is calculated the molecular weightM of the copolymers obtained on the basis of the formula of Cleland andStockmayer:

(b) Basic dyeability: the quantity of Sevron Blue 2G dyestufi fixed froma 7 gram per liter solution in 2 hours at the boil,

(0) Color of the polymer: measured by a General Electric IntegratorSpectrophotometer and expressed as values of purity (P) and brightness(B) as calculated from the tristimulus values derived from thespectrophotometer by the methods recommended by the Standard Observerand Coordinate System of the International Commission on 11- lumination,as fully set forth in the Handbook of Colorimetry, published by TheTechnology Press, Massachusetts Institute of Technology, in 1936.

The results obtained in comparative tests between a copolymer free ofany carboxylic acid monomers, Ex-

in Table 1 above, the quantity of monomers added has been expressed asmilliequivalents of carboxylic acid per 100 grams of mixture of monomersin order to establish a significant comparison. The respectivequantities of cinnamic acid and the other carboxylic acids as apercentage by weight of the monomer mixture employed is also set out inTable 1.

In the case of the color measurements, the purity, P, indicates howclose the shade of color is to neutral color {white-gray-black axis ofthe color). The brightness, B, indicates how close the color of thesample, measured by reflectance of the incident light, is to white.

All of the above polymers were spun under identical conditions from adimethylformamide solution by normal wet spinning procedures into acoagulating bath of dimetliylformamide and water, oriented bystretching, washed in boiling water, dried and collected. As a result ofthese spinnings, fibers were obtained having the propertles set out inTable 2 below:

TABLE 2 Fiber of copoly- Color of the fiber Dyebath exhausmers ofExample tion, percent Purity Brightness dyestufi on the fiber The dyeingtests on the fiber were carried out by dyeing the staple fiber at theboil for three hours with a liquor/fiber ratio of 5011, using the basicdyestuif Astrazon Red BBL (not yet classified in the Color Index), andin Table 2 above there is indicated the maximum concentration ofdyestuff, expressed as percent by weight on the fiber, at which completeexhaustion of the dye bath is obtained.

Examples 11 and 12 A monomer mixture composed of 91 percentacrylonitrile and 9 percent methyl acrylate is polymerized by the methodof Example 1. Under these standard polymerization conditions there areobtained about 300 grams per hour of copolymer in which theacrylonitrile and methyl acrylate are copolymerized in proportions of 93parts of acrylonitrile to 7 parts of methyl acrylate. The resultingcopolymer has an intrinsic viscosity of 1.6, the amount of dyestuffabsorbed from a solution of 7 grams per liter of Sevron Blue 26 is11.1%, and the polymer has a purity of 1.5 and a brightness of 94.7.

The same polymerization as above is repeated by adding to the monomermixture 3.4 milliequivalents of cinnamic acid per 100 grams of monomers(0.5% by weight). Under the standard polymerization conditions theamount of copolymer obtained is 300 grams per hour. The amount of methylacrylate present in the copolymer is 7 percent. The intrinsic viscosityof the copolymer is 1.67, the amount of dyestufi absorbed from asolution of 7 grams per liter of Sevron Blue 26 is 16.5%, and thepolymer has a purity of 1.7 and a brightness of 95.2.

Examples 13 and 14 A monomer mixture composed of 91 percentacrylonitrile and 9 percent methyl methacrylate is polymerized by themethod of Example 1 above. Under these standard polymerizationconditions there are obtained about 300 grams per hour of copolymer inwhich the acrylonitrile and the methyl methacrylate are copolymerized inproportions of 93 parts of acrylonitrile to 7 parts of methylmethacrylate. The copolymer has an intrinsic viscosity of 1.58, theamount of dyestufi" absorbed from a solution of 7 grams per liter ofSevron Blue 2G is 11.5%, and the resulting polymer has a purity of 1.7and a brightness of 94.0.

The same polymerization as above was repeated by adding to the monomermixture 3.4 milliequivalents of cinnamic acid per 100 grams of monomers(0.5% by weight). The amount of copolymer obtained under standardpolymerization condtions is 300 grams per hour. The methyl methacrylateis present in the copolymer to 7%. The intrinsic viscosity of thecopolymer is 1.56, the amount of dyestufi absorbed from a solution of 7grams per liter of Sevron Blue 26 is 16.8%, and the resulting polymerhas a purity of 1.4 and a brightness of 94.5.

Example 15 The polymerization method of Example 1 is repeated by feedinga monomer mixture composed of 92% acrylonitrile by weight, 8% vinylacetate by weight and methyl cinnamic acid in an amount of 3.4milliequivalents per 100 grams of monomers (0.5% by weight). Undernormal polymerization conditions there are obtained 300 grams ofcopolymer per hour in which the acrylonitrile and vinyl acetate arecopolymerized in proportions of 94 parts of acrylonitrile to 6 parts ofvinyl acetate. The copolymer has an intrinsic viscosity of 1.52, theamount of dyestutf absorbed from the 7 gram per liter solution of SevronBlue 2G is 17% and the polymer has a purity of 1.9 and a brightness of93.6.

Examples 16 and 17 There is polymerized by the method of Example 1, amonomer mixture composed of 92 perecnt acrylonitrile and 8 percent vinylacetate. These standard polymerization conditions result in theformation of about 300 grams per hour of copolymer in which theacrylonitrile and vinyl acetate are copolymerized in proportions of 94parts of acrylonitrile and 6 parts of vinyl acetate having a specificviscosity of 0.26, when 0.1 gram of the copolymer is dissolved in 100ml. of N,N-dimethylformamide at 20 C. A blend of the above copolymer wasprepared by blending 88 parts of this copolymer with 12 parts of acopolymer of approximately 50 percent acrylonitrile and 50 percent2-methyl-5-vinyl pyridine and the polymer blend dissolved in the mutualsolvent dimethylacetamide. The above polymer dope was spun into fibersfrom said solution by normal wet-spinning procedures, oriented, washedand dried as in Example 1 above. The resulting fiber was dyed from a dyebath of the basic dyestufi Astrazon Red BBL using a liquor/fiber ratioof 50:1 and the maximum concentration of dyestuif expressed as percentby weight on the fiber at which complete exhaustion of the dye bath isobtained, as in Table 2, Example 1 above, was 1.10%

There was spun by the method of Example 1 an identical monomer mixtureof 92 percent acrylonitrile and 8 percent vinyl acetate but alsocontaining 6.8 milliequivalents of cinnamic acid per grams of monomermixture (1.0% by weight). Under the standard polymerization conditionsof Example 1 there was obtained about 300 grams per hour of copolymer inwhich the acrylonitrile and vinyl acetate are copolymerized inproportions of 94 parts of acrylonitrile to 6 parts of vinyl acetate.The said polymer had a specific viscosity of 0.26 when measured as setforth above. This polymer in an amount of 88 parts was blended with 12parts of a copolymer of 50 percent acrylonitrile and 50 percent 2-methyl-S-vinyl pyridine and wet spun under identical conditions as setforth above. However, in the fibers produced from the latter polymerblend the maximum concentration of dyestuil, expressed as percent byweight on the fiber at which complete exhaustion of a 50:1 liquor tofiber ratio dye bath of the same dyestutf is obtained, was 1.75%.

Examples 16 and 17 clearly demonstrate the superior dyeability withbasic dyestulfs realized in blends of copolymers when one of the blendedcopolymers contains as a co-monomer cinnamic acid or derivatives in theamounts specified by the present invention.

One skilled in the art of the field of acrylic polymers and fibers willreadily realize the advantages resulting from the use of cinnamic acidand its derivatives. To realize the same dyeability, there can beemployed for the spinning of filaments and fibers a copolymer having amolecular weight of 175,000 (N :20 instead of 120,000 N=1.54), asdemonstrated in Examples 1 and 3 above, with advantages both in theproperties of the fiber because of the high molecular weight and in thewhiteness thereof. With smaller increases in molecular weight or withlarger content of cinnamic acid or its derivatives in accordance withthe invention, the dyeability can be increased to about twice the valueof the control polymer. Comparison with the other carboxylic acidmonomers already suggested by the art clearly shows how much moreeffective cinnamic acid is as a means of increasing the basic dyeabilityof acrylic polymers and blends. Furthermore, Examples 16 and 17 clearlydemonstrate that the improvement in basic dyeability as well as inwhiteness and textile properties realized in copolymers are likewiserealized in the fibers produced from the blends of acrylonitrilecopolymers previously known in the art.

In conclusion it has been shown that cinnamic acid and its derivativesconstitute a new, extremely useful means of favorably varying thedyeability of acrylonitrile copolymers and blends with the added abilityto select the level thereof. This finding is all the more surprising ifit is recalled that crotonic acid, having a double bond C=C within themolecule rather than at the end, evidently does not copolymerize, orcopolymerizes only to an insignificant extent, with acrylonitrile, asshown by the fact that the basic dyeability of the resulting copolymeris not changed, cf. Example 10. Cinnamic acid has in common withcrotonic acid the characteristic of the double bond C=C within themolecule rather than at the end, as has been true of the othercarboxylic acid monomers suggested previously, and it is known thatgenerally this property interferes with the ease of polymerization. Inspite of the fact of the presence of the double bond within the moleculerather than at the end, however, cinnamic acid polymerizes readily withacrylonitrile and all other copolymerizable vinyl monomers, as has beendemonstrated above.

As many widely differing embodiments of this invention may be madewithout departing from the spirit and scope thereof, it is to beunderstood that the invention is not limited to the specific embodimentsexcept as defined in the appended claims.

What is claimed is:

1. A fiber-forming composition of matter of improved R HH wherein R isselected from the group consisting of a lower alkyl radical and ahalogen and n is an integer of from to 3 inclusive.

2. The composition of matter of claim 1 wherein the copolymerizablemonolefinic monomer (b) is vinyl acetate.

3. The composition of matter of claim 1 wherein the copolymerizablemonolefinic monomer (b) is vinylidene chloride.

4. The composition of matter of claim 1 wherein the carboxylic acid (c)is cinnamic acid.

5. The composition of matter of claim 1 wherein the carboxylic acid (c)is p-methyl cinnamic acid.

6. The composition of matter of claim 1 wherein the carboxylic acid (c)is o-methyl cinnamic acid.

7. The composition of matter of claim 1 wherein the carboXylic acid (c)is 2,4-dimethyl cinnarnic acid.

8. The compositon of matter of claim 1 wherein the carboxylic acid (c)is 2,4-diethyl cinnamic acid.

9. A fiber-forming composition of matter of improved basic dyeabilitycomprising a copolymer containing in polymerized form about 94 percentby weight of acrylonitrile, about 6 percent by weight vinyl acetate andfrom 0.05 to 1.0 percent by weight of cinnamic acid.

10. A fiber-forming composition of matter of improved basic dyeabilitycomprising a copolymer containing in polymerized form about 94 percentby weight of acrylonitrile, about 6 percent by weight of vinyl acetate,and from 0.05 to 1.0 percent by weight of p-methyl cinnamic acid.

11. A fiber-forming composition of matter of improved basic dyeabilitycomprising a polymer blend of:

(A) 80 to 98 percent by weight of a copolymer containing in polymerizedform:

(a) at least 80 percent by weight of acrylonitrile,

(b) up to 19.95 percent by Weight of at least one other copolymerizablemono-olefinic monomer selected from the group consisting of vinylacetate and vinylidene chloride,

(c) and from 0.05 to 2.0 percent by weight of a carboxylic acid of thegeneral formula Rn H H wherein R is selected from the group consistingof a lower alkyl radical and a halogen and n is an integer of from 0 to3 inclusive.

(B) and 2 to 20 percent by weight of a copolymer containing inpolymerized form:

(a) 10 to 70* percent by weight of acrylonitrile, (b) and 30 to 90percent by weight of a vinylsubstituted tertiary N-heterocyclic amine,

(C) said blend being so proportioned that the vinylsubstituted tertiaryN-heterocyclic amine comprises from 2 to 10 percent by weight of theblend.

12. The composition of matter of claim 11 wherein the vinyl substitutedtertiary N heterocyclicamine is 2-methyl-5-vinyl pyridine.

13. The composition of matter of claim 11 wherein the copolymerizablemono-olefinic monomer (Ab) is vinyl acetate.

14. A fiber-forming composition of matter of improved basic dyeabilitycomprising a polymer blend of:

(A) to 98 percent by weight of a copolymer containing in polymerizedform:

(a) about 94 percent by weight of acrylonitrile, (b) about 6 percent byweight of vinyl acetate, (c) from 0.05 to 1.0 percent by weight ofcinnamic acid,

(B) and 2 to 20 percent by weight of a copolymer containing inpolymerized form:

(a) about 50 percent by weight of acrylonitrile, (b) and about 50percent by weight of 2-methyl- 5-vinylpyridine,

(C) said blend being so proportioned that the 2-methyl- 5-vinylpyridinecomprises from 2 to 10 percent by weight of the blend.

15. The composition of claim 14 wherein the Z-methyl- 5-vinylpyridine(C) comprises about 6 percent by weight of the blend.

16. A method of producing a fiber-forming composition of matter ofimproved basic dyeability comprising:

(A) copolymerizing under polymerization conditions a mixture ofcopolymerizable mono-olefinic monomers comprising:

(a) at least 80 percent by weight acrylonitrile,

(b) up to 19.95 percent by weight of at least one other copolymerizablemono-olefinic monomer selected from the group consisting of vinylacetate and vinylidene chloride,

(c) and from 0.05 to 2.0 percent by weight of a carboxylic acid of thegeneral formula Rn HH wherein R is selected from the group consisting ofa lower alkyl radical and a halogen and n is an integer of from 0 to 3inclusive, (B) in the presence of a polymerization catalyst therefor,(C) and washing and recovering the resulting copolymer. 17. The methodof claim 16 wherein (a) the mixture of copolymerizable mono-olefinicmonomers (A) is polymerized in an aqueous medium, (b) and thepolymerization catalyst (B) is a redox catalyst system. 18. The methodof claim 16 wherein the copolymerizable mono-olefinic monomer (b) isvinyl acetate.

19. The method of claim 16 wherein the carboxylic acid (c) is cinnamicacid.

20. The method of claim 16 wherein the carboxylic acid (c) is p-methylcinnamic.

21. A method of producing a fiber-forming composition of matter ofimproved basic dyeability comprising: (A) copolymerizing underpolymerization conditions a mixture of copolymerizable mono-olefinicmonomers comprising:

(a) at least 80 percent by weight acrylonitrile, (b) up to 19.95 percentby weight of at least one other copolymerizable mono-olefinic monomerselected from the group consisting of vinyl acetate and vinylidenechloride, (c) and from 0.05 to 2.0 percent by Weight of a carboxylicacid of the general formula Q-ern HH 11 (C) washing and recovering theresulting copolymer, (D) and blending 80 to 9 8 percent by weight of theresulting copolymer with from 2 to 20 percent by weight of a copolymercontaining in polymerized form:

(a) 10 to 70 percent by weight of acrylonitrile,

(b) and 30 to 90 percent by weight of a vinylsubstituted tertiaryN-heterocyclic amine,

(c) said blend being so proportioned that the vinylsubstituted tertiaryN-heterocyclic amine comprises from 2 to 10 percent by weight of theblend.

22. The method of claim 21 wherein (a) the copolymerizable mono-olefinicmonomer (Ab) is vinyl acetate,

(b) the carboxylic acid (Ac) is cinnamic acid,

(c) and the vinyl-substituted tertiary N-heterocyclic amine (Db) isZ-methyl-S-vinylpyridine.

23. A basic dyeable textile fiber of the composition of claim 1.

24. A basic dyeable textile fiber of the composition of claim 9.

25. A textile fiber of the composition of claim 1 dyed with a basic dye.

26. A basic dyeable textile fiber of the composition of claim 11.

27. A basic dyeable textile fiber of the composition of claim 14.

28. A textile fiber of the composition of claim 11 dyed with a basicdye.

References Cited UNITED STATES PATENTS 2,866,763 12/1958 Sanders260-80.5 2,890,148 6/1959 Dede 26080.5 3,028,371 4/1962 Wishman et al260-805 3,029,214 4/1962 Hobson 260-895 MURRAY TILLMAN, PrimaryExaminer.

E. E. WOODRUFF, D. J. BREZNER, M. J. TULLY Assistant Examiners.

1. A FIBER FORMING COMPOSITION OF MATTER OF IMPROVED BASIC DYEABILITYCOMPRISING A COPOLYEMR CONTAINING IN POLYMERIZED FORM: (A) AT LEAST 80PERCENT BY WEIGHT OF ACRYLONITRILE, (B) UP TO 19.95 PERCENT BY WEIGHT OFAT LEAST ONE OTHER COPOLYMERIZABLE MONO-OLEFINC MONOMER SELECTED FROMTHE GROUP CONSISTING OF VINYL ACETATE AND VINYLIDENE CHLORIDE, (C) ANDFROM 0.05 TO 2.0 PERCENT BY WEIGHT OF A CARBOXYLIC ACID OF THE GENERALFORMULA